Leaf springs are widely used for springably supporting the sprung mass of a motor vehicle with respect to an axle (usually the rear axle) adjacent a wheel. A leaf spring is composed of a number of stacked leaves of progressively longer length, increasing from a shortest leaf disposed adjacent the axle to a longest leaf disposed distal from the axle. The leaf spring is connected at its central portion to the axle, for example via U-bolts and a bracket. Each end of the longest leaf has an end fitting for connecting to the sprung mass. The leaf spring forms a semi-elliptical shape in which the concave shape thereof faces away from the axle.
At a generally medial location between the leaf spring central portion and each end fitting is disposed a clinch clip which serves to engird the leaves thereat so that the leaves can flex and yet be kept clinched together in a closely stacked configuration. In this regard, FIGS. 1A through 1D show an example of a prior art clinch clip 10, wherein FIG. 1A depicts a typical example of operation with respect to a leaf spring 12, an axle A and sprung mass M.
As depicted at FIG. 1C, the leaf spring 12, includes a plurality of leaves 12L, a longest 12a, a shortest 12b and, merely by example, several additional leaves 12c, 12d, 12e disposed in between.
As shown best at FIGS. 1B and 1D, the prior art clinch clip 10 is composed of an upper clip member 14 and a lower clip member 16, each having a U-shape. The upper clip member 14 has a first lateral bar 14a to which at either end thereof is integrally connected a perpendicular first leg 14b, 14c. The lower clip member 16 has a second lateral bar 16a (disposed in parallel relation to the first lateral bar 14a) to which at either end thereof is integrally connected a perpendicular second leg 16b, 16c (each disposed in parallel relation to the first legs 14b, 14c). A cylindrical rivet 18 connects the shortest leaf 12b, via a circular hole 20 formed therein, to the second lateral bar 16a, via a circular hole 22 formed therein. The upper clip member 14 is connected to the lower clip member 16 via first and second pairs of aligned circular holes 24a, 24b formed in a superposition 26 of the first and second legs, respectively, through which a cylindrical bolt 28 passes and is tightly secured thereto by a nut 30 threaded onto end threads of the bolt. A relatively large, generally U-shaped elastomeric spacer 32 is provided, having a pair of robust sidewalls 32a, 32b interconnected by a relatively thin bottom wall 32c disposed between the shortest leaf 12b and its adjacent leaf.
As can be understood from FIGS. 1C and 1D, the leaves 12L of the leaf spring 12 pass into the clinch clip 10. In this regard, the first lateral bar 14a is disposed parallel to the flat upper surface 34 of the longest leaf 12a, the second lateral bar 16a is disposed parallel to the flat of the shortest leaf 12b, and the first legs are disposed parallel to the edges 12g of the leaves. The sidewalls 32a, 32b of the spacer 32 serve to locate the first legs 14b, 14c with respect to the leaf edges 12g, as well as provide a sliding interface therebetween.
In operation, as shown at FIG. 1A, the leaf spring 12 is connected at its central portion 12f to the axle A, and each end of the longest leaf 12a is an end fitting 42a, 42b for connecting to the sprung mass M. The prior art clinch clip 10 keeps the leaves of the leaf spring 12 clinched together in a compact configuration as the axle moves in relation to the sprung mass.
Problematically, since the prior art clinch clip 10 is free to rotate around the bolt axis B (see arrow AB of FIG. 1B) and free to rotate around the (relatively perpendicular) rivet axis R (see arrow AR of FIG. 1B), when under high force and/or the spacer 32 has failed, the prior art clinch clip 10 can squeak in relation to the leaf spring, and/or the longest leaf may generate a “helicopter-like” noise relative to its adjoining leaf, and/or the prior art clinch clip 10 may rotate on either or both the bolt and rivet axes, disrupting the functionality of the leaf spring due to the undesirable load path management of the leaves during operation.
Accordingly, what remains needed in the art is a clinch clip which can somehow be rotationally restrained around the bolt and rivet axes, and yet can be configured such that the attachment of the upper and lower clip members has a compact packaging.